Electrically commutated, brushless direct current (dc) inductive motors are used in a wide variety of commercial applications. A common application of such a motor is in spindle motor for data storage device. Spindle motors rotate one or more axially aligned data recording discs at a constant high speed. As the discs are rotated, data transducing heads are controllably moved across the disc surfaces to access tracks to which data are stored.
Spindle motors incorporate a stationary stator portion supporting multiple phase windings, electrically connected in a star or delta configuration. A rotatable rotor supports a corresponding array of permanent magnets adjacent the windings.
The rotor is rotated by sequentially, electrically commutating the phase windings. During each commutation period, a drive current is input to one phase, output from another phase, and the remaining phase(s) are held at high impedance.
Market pressures continue to push for electronic devices with improved response times and reliability. As such, challenges remain and a need persists for improvements in the area of motor control, to which the present invention is directed.